JPH06102934A - Home position stop device - Google Patents

Abstract

PURPOSE:To surely stop a traveling object to a home position by calculating speed when the traveling object passes through a brake start point provided on a place at a prescribed distance from the home position, calculating deceleration so that it stops at the home position and controlling a motor. CONSTITUTION:The motor 17 is rotated by a shift signal to the home position, and the traveling object is shifted to the direction of the home position. A speed calculation part 12 divides the distance between slits by a pulse outputted from a sensor 22 whenever the traveling object passes through the slits 19 and by time with the pulse so as to calculate speed. A brake start point detection part 11 detects the pulse when the object passes through a brake start point slit 21 and detects the brake start point. When a deceleration calculation part 14 calculates deceleration from speed calculated in the calculation part 12 and it outputs deceleration to a motor driving part 16 through a switching part 15, the driving part 16 drives the motor 17 so that speed comes to calculated deceleration. When the home position is detected in the detection part 13, deceleration is set to '0' and the traveling object is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a home position stopping device for moving and stopping a pickup in an optical disk device, a magneto-optical disk device, a magnetic disk device or the like to a home position.

[0002]

2. Description of the Related Art A home position is determined in a magneto-optical disk device, a magneto-optical disk device, a magnetic disk device, etc., and a pickup is moved to the home position, stopped, and made to stand by until the next command. There is.

A conventional method for stopping the pickup at the home position will be described with reference to FIG. Figure 3 (A)
In the above, 1 is a disc, 2 is a pickup, 3 is an actuator, 4 is a scale, and 5 is a sensor.

The scale 4 is attached to a moving body, and the sensor 5 is fixed. The scale 4 is shown in FIG.
As shown in (B), slits 6 are provided at equal intervals, and a home position slit 7 indicating a home position is also provided. When the actuator 3 is driven, the pickup 2 and the scale 4 also move,
As the scale 4 moves, the sensor 5 detects light from a light source (not shown) through the slit 6, and the home position slit 7 detects that the home position is reached.

As a conventional method of moving the pickup to the home position, the actuator 3 is instructed by a command.
When the sensor 5 detects light from the home position slit 7 provided on the scale 4, the motor of the actuator 3 is driven in the reverse direction to apply the brake. I was trying to stop it.

[0006]

As described above, in a device such as an optical disk, when the pickup is moved to the home position, after detecting the marker indicating the home position of the scale attached to the moving body,
The motor was rotated in reverse and the brake was applied to stop it.

Since the brake for rotating the motor in the reverse direction to stop the motor is constant regardless of the speed of the moving body, therefore, the brake can be stopped within the home position depending on the speed at which the marker indicating the home position is passed. Instead, the operation to return to the home position was performed again.

It is an object of the present invention to provide an improved home position stopping device which adjusts and controls a brake according to the speed of a moving body to surely stop a pickup within a home position.

[0009]

Means adopted by the present invention for solving the above-mentioned problems will be described. A device for stopping a moving object at a home position, wherein a brake start point is provided at a distance x _B from the home position, and it is detected that the object has passed the brake start point when moving toward the home position. a brake start point detecting unit, and a velocity calculator for calculating a velocity v _B when passing the object is detected by the brake start point detecting unit, reduced than the rate calculated by the velocity calculation unit v _B and the distance x _B Speed α _B
And a deceleration calculation unit that calculates (= v _B ² / 2x _B ) and outputs it to the motor drive unit.

[0010]

First, the principle of the present invention will be described. Kinetic energy E _m when mass m becomes an object is moving at a velocity v _B is ^{_{E m = mv B 2/2}} ··· (1).

Further, the energy E _B when the mass m becomes an object moves distance x _B in acceleration alpha _B, an _{E B = mα B x B ···} (2).

Accordingly, the mass m, velocity v in is stopped at a point where the moving object moves distance x _B in _B formula (1) and from ^{_{(2), mv B 2/}} 2 = mα B x B · ... (3) ^{_{and, α B = v B 2 /}} 2x B ··· can be stopped if brought into deceleration (4) becomes the deceleration.

The present invention is based on this principle, and the brake starting point is provided at a position at a distance x _B from the home position. When the brake start point detection unit detects that the moving body has passed the brake start point, the speed calculation unit calculates the speed v _B when the moving body has passed the brake start point.

In the deceleration calculation unit, the deceleration α which is v _B ² / 2x _B from the speed v _B calculated by the speed calculation unit and the distance x _B.
B is calculated and output to the motor drive unit. The motor drive unit controls the rotation of the motor so as to achieve this deceleration. As described above, the brake start point is provided at a position distance x _B from the home position, and when the moving body passes the brake start point, the speed at the time of passing is calculated, and the deceleration is calculated so as to stop at the home position. Since the motor is controlled, the moving body can be reliably stopped at the home position.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of the first embodiment. In FIG. 1, 11 is a brake start point detection unit that detects a brake start point, 12 is a speed calculation unit that calculates a speed when passing through the brake start point, 13 is a home position detection unit that detects a home position, and 14 is A deceleration calculation unit that calculates deceleration, 15 is a switching unit, 16 is a motor drive unit, 17 is a motor, 18 is a scale attached to a moving body,
19 is a slit indicating the position of the moving body, 20 is a home position slit, 21 is a brake start point slit, 22
Is a sensor.

The brake starting point slit 21 is provided at a position separated from the home position slit 20 by a distance x _B. Further, the slits 19 are provided at equal intervals. Next, the operation of the embodiment will be described. The switching unit 15 is switched to the movement signal to the home position by the control unit (not shown) and outputs the signal to the motor drive unit 16.

The motor drive unit 16 rotates the motor 17 by the movement signal to the home position, and moves a moving body (not shown) toward the home position. When the moving body moves, the scale 1 attached to the moving body
8 moves at the same time. The slits 19 of the scale 18 are provided at equal intervals. Therefore, the speed calculation unit 12 calculates the speed by dividing the distance between the slits by the time between the pulse output each time the sensor 22 passes through the slit 19.

The brake start point detection unit 11 includes a scale 1
The pulse output from the sensor 22 when passing through the brake start point slit 21 of No. 8 is detected to detect the brake start point. Further, the home position detection unit 13 detects the pulse output from the sensor 22 when passing through the home position slit 20 of the scale 18 to detect the home position.

In the deceleration calculation section 14, the brake start inspection
When the brake start point is detected by the output unit 11, the speed calculation unit
Speed v output from 12_BSubstitute into equation (4) to decelerate
Degree α _BIs calculated and output to the switching unit 15. In the switching unit 15
Is detected by the brake start point detection unit 11.
Then, the signal input from the deceleration calculation unit 14
The switching is performed so that the data is output to the data driving unit 16.

The motor drive section 16 drives the motor 17 so that the deceleration rate becomes α _B. Home position detector 13
When the home position is detected by, the deceleration calculation unit 14
To set the deceleration to 0, that is, the drive current of the motor 17 to 0. Next, a second embodiment will be described with reference to FIG.

First, the principle of the second embodiment will be described. The relationship between the velocity v _B , the distance x _B and the deceleration α _B is given by the equation (4) as described above. Therefore, _assuming that the maximum speed when moving to the home position is v _max and the deceleration when decelerating is also maximal α _max , the distance x until deceleration and stop x
_B is given by x _B = v _max ² / 2α _max (5)

The second embodiment is based on this principle, and in FIG. 2, the brake start point detection unit 11, the home position detection unit 13, the switching unit 15, the motor drive unit 1 are shown.
6, motor 17, scale 18, slit 19, home position slit 20, brake start point slit 2
1. The sensor 22 is as described in FIG.

Reference numeral 23 is a maximum speed generator for generating a signal for setting the maximum speed v _max when moving the moving body to the home position. Reference numeral 24 is a maximum deceleration generating unit that generates a maximum deceleration α _max when the moving body is stopped.

The position of the brake start point slit 21 is the distance x from the home position slit 20 expressed by the equation (5).
_It will be installed at point _B. When the moving body is moved to the home position, the maximum speed generation section 23 passes the switching section 15 to generate a signal of the maximum movement speed v _max to the motor drive section 16 to drive the motor 17. Therefore, the speed when the moving body moves and the brake start point slit 21 passes the sensor 22 is v _max .

When the brake start point detecting section 11 detects the brake start point, the switching section 15 performs switching,
From the maximum deceleration generator 24, a signal that gives the maximum deceleration α _max is sent out and input to the motor drive unit 16 to drive the motor 1
Decelerate 7. When the home position is detected by the home position detector 13, the output from the maximum deceleration generator 24 is set to zero. At this time, as described above, the energy of motion and the energy required to decelerate are equal,
The moving body is in a stopped state.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment and various modifications can be made.

[0027]

As described above, according to the present invention, the following effects can be obtained. A braking start point is provided at a distance x _B from the home position, and when the moving body passes the braking start point, the speed at the time of passing is calculated, the deceleration is calculated to stop at the home position, and the motor is controlled. Therefore, the moving body can be reliably stopped at the home position.

The maximum speed for moving the moving body to the home position is v _max, and the maximum deceleration for stopping the moving body is also α _{max. The} point where deceleration is started is the distance x _B = v from the home position. _Since it is provided at the point of _max ² / 2α _max , the moving body can be reliably moved to the home position in a short time.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 11 Brake Start Point Detection Section 12 Speed Calculation Section 13 Home Position Detection Section 14 Deceleration Calculation Section 15 Switching Section 16 Motor Drive Section 17 Motor 18 Scale 19 Slit 20 Home Position Slit 21 Brake Start Point Slit 22 Sensor 23 Maximum Speed Generation Section 24 Maximum deceleration unit

Claims (2)

[Claims] 1. A device for stopping a moving object at a home position, wherein a brake starting point is provided at a distance x _B from the home position, and the object passes through the brake starting point when moving toward the home position. and a brake start point detecting unit for detecting that was, a speed calculation unit for calculating a velocity v _B when the passage of an object is detected by the brake start point detecting unit, the speed calculated by the speed calculator v _B And a deceleration calculation unit that calculates a deceleration α _B (= v _B ² / 2x _B ) from the distance x _B and outputs the deceleration α _B (= v _B ² / 2x _B ) to the motor drive unit. 2. A device for stopping a moving object at a home position, comprising: a maximum speed generator for generating a signal for moving a moving speed to the home position at a maximum speed v _max; and a maximum speed for stopping a motor. A maximum deceleration generator that generates a signal for deceleration at deceleration α _max and a brake start point at a distance x _B (= v _max ² / 2α _max ) from the home position are provided so that the object moves toward the home position. A brake start point detection unit that detects that the brake start point has been passed, and an output from the maximum speed generation unit when the passage of an object is detected by the brake start point detection unit becomes an output from the maximum deceleration generation unit. A home position stopping device, comprising: a switching unit that switches and outputs to a motor drive unit.